title: Evaluation of changes in left ventricular myocardial function observed in canine myocardial dysfunction model using a two-dimensional tissue tracking technique.
abstract: This study was conducted to assess the ability of two-dimensional tissue tracking (2DTT) to evaluate changes in left ventricular (LV) myocardial function associated with sustained high electrical pacing. Pacemakers were implanted at the right ventricular (RV) apex of five female Beagles, and sustained high electrical pacing of 250 beats per minute (bpm) was performed for three consecutive weeks. Conventional echocardiography and 2DTT were performed at baseline, and at every week for three weeks with pacing. The baseline parameters were then compared to those of weeks 1, 2, and 3. Three weeks of pacing resulted in significant reduction of radial and circumferential global strains (p < 0.001). Regional analysis revealed reduction of segmental strains in both radial and circumferential directions, as well as increased dyssynchrony after three weeks of pacing in the radial direction (p = 0.0007). The results of this study revealed the ability of 2DTT to measure radial and circumferential strains in dogs with sustained high-electrical pacing, and allowed assessment of global and regional myocardial function and the degree of dyssynchrony.
authors.affiliation: Departments of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
authors.forename: Lina
authors.initials: L
authors.lastname: Hamabe
authors.forename: Ryuji
authors.initials: R
authors.lastname: Fukushima
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kawamura
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Shinoda
authors.forename: Hsu
authors.initials: H
authors.lastname: Huai-Che
authors.forename: Shuji
authors.initials: S
authors.lastname: Suzuki
authors.forename: Derya
authors.initials: D
authors.lastname: Aytemiz
authors.forename: Toshiroh
authors.initials: T
authors.lastname: Iwasaki
authors.forename: Ryou
authors.initials: R
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D002304:Cardiac Pacing, Artificial; D004285:Dogs; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D016277:Ventricular Function, Left
keywords: cardiology; dog; echocardiography; experimental animal model; myocardial failure